Low volatile tackifier compositions

ABSTRACT

A tackifier composition comprising at least one thermoplastic hydrocarbon resin and an antioxidant composition is provided; wherein a portion of the volatile organic compounds in the thermoplastic hydrocarbon resin has been removed; wherein the antioxidant composition comprises at least one primary antioxidant and at least one secondary antioxidant; and wherein the levels of individual volatile organic compound monitored in the tackifier composition are less than about 0.5 ppm as measured by GC/MS headspace analysis. Processes for producing the tackifier composition are also provided as well as adhesives comprising the tackifier compositions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.62/799,383 filed Jan. 31, 2019 and U.S. Provisional Application Nos.62/841,498, 62/841,507, 62/841,511, and 62/841,515 all filed May 1,2019; the entire contents of the provisional applications are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

Public concern for the potential adverse health effects of chemicalsreleased from personal hygiene products and other consumer goods isrising worldwide. Concern translates to pressure on marketers,formulators and chemical raw materials suppliers to work together toreduce odor, volatile organic compounds (VOCs) and trace chemicals inthese goods. Thermoplastic hydrocarbon resins are utilized in adhesivesused in consumer goods as well as personal hygiene products.

To lower the viscosity sufficiently to enable coating onto a consumergoods, adhesives are applied at high temperatures. For example, mostpersonal hygiene manufacturers heat the adhesive to temperaturesexceeding 130° C. before application to nonwoven materials. Volatilesubstances in the raw materials of the adhesive may be released duringthis coating process, and additional VOCs can be created by chemicalreactions that occur in the adhesive composition. For example, VOCs canbe generated due to degradation of thermoplastic hydrocarbon resinsduring down stream blending or/and dispensing processes. Thesesubstances may be vented to the environment or absorbed by otherpersonal hygiene article components, such as nonwoven webs. Because hotmelt adhesives function by cooling rapidly to form a strong bond betweentwo substrates, they can also ‘lock in’ VOCs from any source. Oftentimes, personal hygiene goods are sealed into plastic packagingimmediately after manufacturing. Personal hygiene article manufacturingis a high-speed process; no opportunity for venting VOCs exists prior toconsumer use of the product. When the consumer opens the packaging, theymay notice the odor caused by whichever odorous volatile substances arepresent in concentrations high enough for the consumer to perceive.

Thermoplastic hydrocarbon resins (tackifiers) are one of the criticalcomponents of adhesives for hygiene, packaging, automotive, woodworkingand other applications. Therefore, there is a need in these industriesfor thermoplastic hydrocarbon resins having lower odor and volatileorganic compound content and when processed into adhesives and consumergoods, less or no odor causing compounds and/or volatile organiccompounds are generated.

BRIEF SUMMARY OF THE INVENTION

In one embodiment of the invention, a tackifier composition comprisingat least one thermoplastic hydrocarbon resin and an antioxidantcomposition; wherein a portion of the volatile organic compounds in thethermoplastic hydrocarbon resin has been removed; wherein theantioxidant composition comprises at least one primary antioxidant andat least one secondary antioxidant; and wherein the levels of individualvolatile organic compounds monitored of in the tackifier composition areless than about 0.5 ppm as measured by GC/MS headspace analysis asdescribed in this disclosure.

In another embodiment of the invention, a tackifier composition isprovided comprising at least one thermoplastic hydrocarbon resin and anantioxidant composition; wherein a portion of the volatile organiccompounds in the thermoplastic hydrocarbon resin has been removed;wherein the antioxidant composition comprises at least one primaryantioxidant, optionally at least one secondary antioxidant, and at leastone hindered amine light stabilizer (HALS); and wherein the levels ofindividual volatile organic compound monitored in the tackifiercomposition are less than about 0.5 ppm as measured by GC/MS headspaceanalysis described in this disclosure.

In another embodiment of the invention, a process for producing atackifier composition is provided comprising: a) removing a portion ofthe volatile organic compounds from a thermoplastic hydrocarbon resin;and b) adding an antioxidant composition to the thermoplastichydrocarbon resin; wherein the adding is completed by at least one ofthe following methods: i) at least a portion of at least one antioxidantof the antioxidant composition is added to the thermoplastic hydrocarbonresin prior to step (a); ii) at least a portion of at least oneantioxidant in the antioxidant composition is added to the thermoplastichydrocarbon resin after step (a); iii) at least a portion of at leastone antioxidant in the antioxidant composition is added to thethermoplastic hydrocarbon resin before and after step (a) to produce thetackifier composition; wherein the antioxidant composition comprises atleast one primary antioxidant, optionally one secondary antioxidant, andat least one hindered amine light stabilizer (HALS); and wherein thelevels of individual volatile organic compound monitored in thetackifier composition are less than about 0.5 ppm as measured by GC/MSheadspace analysis described in this specification.

In another embodiment of this invention, an adhesive is providedcomprising the tackifier compositions previously described.

In another embodiment of this invention, an article is providedcomprising the adhesive.

This invention focuses on reducing odor and VOCs of any thermoplastichydrocarbon resins and tackifier compositions. Odor and VOC levels ofthe hydrocarbon resins are of great importance for several applications,such as, but not limited to, hygiene, packaging, product assembly andbuilding/constructions. Specifically, in hygiene applications, odor canbe caused by certain monomers and/or solvents which either exist in thethermoplastic hydrocarbon resin or are generated during downstreamcustomers' blending processes. Therefore, reducing levels of thesevolatiles and preventing their generation under customers' processconditions are two effective ways to reduce odor of thermoplastichydrocarbon resins. In relation to odor, the invention is targeted toreduce the level of certain volatile compounds in partially or fullyhydrogenated thermoplastic hydrocarbon resins. These VOCs of interestmay cause odor and/or possess potential adverse health effect to humanbodies. The total volatile levels will also be certainly reducedsignificantly with the solutions of this invention. The levels ofindividual volatiles of interest can be measured by Headspace GCMS underdifferent conditions.

The steam stripping proposed in this invention can effectively reducethe volatile organic compound content of thermoplastic hydrocarbonresins.

The solutions in this invention include, but are not limited to:

-   -   (1) Steam stripping to remove odor related volatile organic        compounds; and    -   (2) Effective antioxidant packages to stabilize thermoplastic        hydrocarbon resins, so they do not generate additional VOCs or        oligomers in customers' blending process.

A portion of the volatile organic compounds has been removed fromthermoplastic hydrocarbon resins by various methods, and variousantioxidants have been used to help prevent degradation and thus thegeneration of VOCs. However, the combination of this antioxidantcomposition and removal of oligomers by steam stripping is not known inthe art, and provides a tackifier composition with the levels ofindividual VOCs monitored less than about 0.5 ppm as measured by GC/MSheadspace analysis described in this disclosure.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment of the invention, a tackifier composition is providedcomprising at least one thermoplastic hydrocarbon resin and anantioxidant composition; wherein a portion of the volatile organiccompounds in the thermoplastic hydrocarbon resin has been removed;wherein the antioxidant composition comprises at least one primaryantioxidant, optionally at least one secondary antioxidant, and at leastone hindered amine light stabilizer (HALS); and wherein the levels ofindividual volatile organic compounds of interest in the tackifiercomposition are less than about 0.5 ppm as measured by GC/MS headspaceanalysis described in this disclosure.

Certain terms used throughout this disclosure are defined herein belowso that the present invention may be more readily understood. Additionaldefinitions are set forth throughout the disclosure.

Each term that is not explicitly defined in the present application isto be understood to have a meaning that is commonly accepted by thoseskilled in the art. If the construction of a term would render itmeaningless or essentially meaningless in its context, the term'sdefinition should be taken from a standard dictionary.

The use of numerical values in the various ranges specified herein,unless expressly indicated otherwise, are considered to beapproximations as though the minimum and maximum values within thestated ranges were both preceded by the word “about.” In this context,the term “about” is meant to encompass the stated value ±a deviation of1%, 2%, 3%, 4%, or not more than 5% of the stated value. In this manner,slight variations above and below the stated ranges can be used toachieve substantially the same results as the values within the ranges.In addition, the disclosure of these ranges is intended as a continuousrange including every value between the minimum and maximum values.

Unless otherwise indicated, % solids or weight % (wt %) are stated inreference to the total weight of a specific formulation, emulsion, orsolution.

Unless otherwise indicated, the terms “polymer” and “thermoplasticresin” do not necessarily mean the same thing but include bothhomopolymers having the same recurring unit along the backbone, as wellas copolymers having two or more different recurring units along thebackbone. For instance, polymer refers to a molecule having a numberaveraged molecular weight of greater than 5,000 g/mol, as measured byGPC, whereas a “thermoplastic resin” refers to a molecule having anumber average molecular weight of less than 5,000 g/mol, as measured byGPC. Such polymers or thermoplastic resins include but are not limitedto, materials prepared by either condensation, cationic, anionic,Ziegler-Natta, reversible addition-fragmentation chain-transfer (RAFT),or free radical polymerization. Further, the term “thermoplastic resin”or “starting thermoplastic resin” when used alone refers to theunmodified, or non-modified thermoplastic resin. Furthermore, while theterm “polymer” is meant to encompass elastomers, the term “elastomer”does not necessarily encompass all polymers. In other words, as known toone of skill in the art, not all polymers are elastomers.

The term “comprising” (and its grammatical variations) as used herein isused in the inclusive sense of “having” or “including” and not in theexclusive sense of “consisting only of.”

The terms “a” and “the” as used herein are understood to encompass oneor more of the components, i.e., the plural as well as the singular.

The term “C5 thermoplastic resin” as used herein means aliphatic C5hydrocarbon thermoplastic resins that are produced from thepolymerization of monomers comprising C5 and/or C6 olefin speciesboiling in the range from about 20° C. to about 200° C. at atmosphericpressure. These monomers are typically generated from petroleumprocessing, e.g. cracking. The aliphatic C5 hydrocarbon thermoplasticresins of this invention can be produced by any method known in the art.In one embodiment, aliphatic C5 hydrocarbon thermoplastic resins areprepared by cationic polymerization of a cracked petroleum feedcontaining C5 and C6 paraffins, olefins, and diolefins also referred toas “C5 monomers.” These monomer streams are comprised of cationicallypolymerizable monomers such as 1,3-pentadiene which is the primaryreactive component along with cyclopentene, pentene, 2-methyl-2-butene,2-methyl-2-pentene, cyclopentadiene, and dicyclopentadiene. Thepolymerizations are catalyzed using Friedel-Crafts polymerizationcatalysts such as Lewis acids (e.g., boron trifluoride (BF₃), complexesof boron trifluoride, aluminum trichloride (AlCl₃), and alkyl aluminumchlorides). In addition to the reactive components, nonpolymerizablecomponents in the feed include saturated hydrocarbons that are in someinstances co-distilled with the unsaturated components such as pentane,cyclopentane, or 2-methylpentane. Solid acid catalysts can also beutilized to produce aliphatic C5 hydrocarbon thermoplastic resins.Aliphatic C5 hydrocarbon thermoplastic resins include non-hydrogenated,partially hydrogenated, or fully hydrogenated resins. Aliphatic C5thermoplastic resins can be obtained as Piccotac® C5 and Eastotac® C5 H2thermoplastic resins from Eastman Chemical Company (Kingsport, Tenn.,US).

The term “C5/C9 thermoplastic resin” as used herein means analiphatic/aromatic hydrocarbon C5/C9 thermoplastic resin that isproduced from the polymerization of monomers comprising at least oneunsaturated aromatic C8, C9, and/or C10 species boiling in the rangefrom about 100° C. to about 300° C. at atmospheric pressure and at leastone monomer comprising C5 and/or C6 olefin species boiling in the rangefrom about 20° C. to about 200° C. at atmospheric pressure. In oneembodiment, C5 and/or C6 species include paraffins, olefins, anddiolefins also referred to as “C5 monomers.” These monomer streams arecomprised of cationically polymerizable monomers such as 1,3-pentadienewhich is the primary reactive component along with cyclopentene,pentene, 2-methyl-2-butene, 2-methyl-2-pentene, cyclopentadiene, anddicyclopentadiene. In one embodiment, unsaturated aromatic C8, C9,and/or C10 monomers are derived from petroleum distillates resultingfrom naphtha cracking and are referred to as “C9 monomers.” Thesemonomer streams are comprised of cationically polymerizable monomerssuch as styrene, alpha methyl styrene, beta-methyl styrene, vinyltoluene, indene, dicyclopentadiene, divinylbenzene, and other alkylsubstituted derivatives of these components. The cationic polymerizationis in some instances catalyzed using Friedel-Crafts polymerizationcatalysts such as Lewis acids (e.g., boron trifluoride (BF₃), complexesof boron trifluoride, aluminum trichloride (AlCl₃), and alkyl aluminumchlorides). Solid acid catalysts are also utilized to producealiphatic/aromatic C5/C9 hydrocarbon thermoplastic resins. In additionto the reactive components, non-polymerizable components include,aromatic hydrocarbons such as xylene, ethyl benzene, cumene, ethyltoluene, indane, methylindane, naphthalene and other similar specifies.The non-polymerizable components of the feed stream are in someembodiments incorporated into the thermoplastic resins via alkylationreactions. Aliphatic/aromatic C5/C9 hydrocarbon thermoplastic resinsinclude non-hydrogenated, partially hydrogenated resins, andhydrogenated resins. Aliphatic/aromatic C5/C9 thermoplastic resins canbe obtained as Piccotac® thermoplastic resin from Eastman ChemicalCompany. The proportion of C5 to C9 is not limited. In other words, theamount of C5 monomer in the C5/C9 thermoplastic resin can be anywherefrom 0.1 to 100% and vice versa the amount of C9 monomer in the C5/C9thermoplastic resin can be from 0.1 to 100%.

The term “C9 thermoplastic resin” as used herein means an aromatic C9hydrocarbon thermoplastic resin that is a thermoplastic resin producedfrom the polymerization of monomers comprising unsaturated aromatic C8,C9, and/or C10 species boiling in the range from about 100° C. to about300° C. at atmospheric pressure. These monomers are typically generatedfrom petroleum processing, e.g. cracking. The aromatic C9 hydrocarbonthermoplastic resins of this invention can be produced by any methodknown in the art. Aromatic C9 hydrocarbon thermoplastic resins are inone embodiment prepared by cationic polymerization of aromatic C8, C9,and/or C10 unsaturated monomers derived from petroleum distillatesresulting from naphtha cracking and are referred to as “C9 monomers.”These monomer streams are comprised of cationically polymerizablemonomers such as styrene, alpha methyl styrene (AMS), beta-methylstyrene, vinyl toluene, indene, dicyclopentadiene, divinylbenzene, andother alkyl substituted derivatives of these components. Aliphaticolefin monomers with four to six carbon atoms are also present duringpolymerization in some embodiments of C9 resins. The polymerization isin some instances catalyzed using Friedel-Crafts polymerizationcatalysts such as Lewis acids (e.g., boron trifluoride (BF₃), complexesof boron trifluoride, aluminum trichloride (AlCl₃), and alkyl aluminumchlorides). In addition to the reactive components, nonpolymerizablecomponents include, but are not limited to, aromatic hydrocarbons suchas xylene, ethyl benzene, cumene, ethyl toluene, indane, methylindane,naphthalene, and other similar chemical species. The nonpolymerizablecomponents of the feed stream are in some embodiments incorporated intothe thermoplastic resins via alkylation reactions. C9 hydrocarbonthermoplastic resins include non-hydrogenated, partially hydrogenated,or fully hydrogenated resins. Aromatic C9 hydrocarbon thermoplasticresins can be obtained as Picco® C9 thermoplastic resin, and aliphatichydrogenated and aliphatic/aromatic partially hydrogenated C9 H2hydrocarbon thermoplastic resins can be obtained as Regalite®thermoplastic resin from Eastman Chemical Company.

The term “DCPD thermoplastic resin” as used herein meansdicyclopentadiene (DCPD) thermoplastic resin, most commonly formedthrough ring opening metathesis polymerization (ROMP) ofdicyclopentadiene in the presence of a strong acid catalyst, such asmaleic acid or aqueous sulphuric acid, or thermal polymerization.Dicyclopentadiene is also formed in some embodiments by a Diels Alderreaction from two cyclopentadiene molecules and exists in twostereo-isomers: endo-DCPD and exo-DCPD. Typically, greater than 90% ofthe DCPD molecules present in commercial grades of DCPD are in the endoform. DCPD thermoplastic resins include aromatic-modified DCPD resins aswell as hydrogenated, partially hydrogenated, and non-hydrogenatedresins, though in most instances herein only H2 DCPD is described sinceit is the most readily commercially available form of DCPD.Aromatic-modified DCPD is also contemplated as a DCPD thermoplasticresin. Aromatic modification is, for instance, by way of C9 resin oil,styrene, or alpha methyl styrene (AMS), and the like. Hydrogenated andpartially hydrogenated DCPD and hydrogenated and partially hydrogenatedaromatic-modified DCPD resin is commercially available as Escorez®5000-series resin (ExxonMobil Chemical Company, TX, US).

The term “IC thermoplastic resin” or “IC resin” as used herein meansindene-coumarone (IC) thermoplastic resin, i.e. a syntheticthermoplastic terpene resin formed using feedstocks of indene andcoumarone made from heavy-solvent naphtha obtained from the distillationof coal tar, which is a by-product of coke production. Heavy-solventnaphtha is rich in coumarone and indene, but most especially indene, andcan be modified with phenol. These feedstocks can be formed bypolymerization in BF₃ or BF₃ etherates. Catalysts can be removed by analkaline wash or lime after polymerization. The resin can be isolated bysteam distilling off the unreacted naphtha. IC thermoplastic resins canbe used as plasticizers, and secure stress-strain properties at highlevels. Examples of such resins include Novares® C indene-coumarone andNovares® CA phenol-modified indene-coumarone thermoplastic resin, whichare commercially available from Rutgers Germany GmbH., Duisburg,Germany.

The term “PMR” as used herein means pure monomer thermoplastic resins.Pure monomer thermoplastic resins are produced from the polymerizationof styrene-based monomers, such as, styrene, alpha-methyl styrene, vinyltoluene, and other alkyl substituted styrenes. Pure monomerthermoplastic resins are produced by any method known in the art. Puremonomer feedstock for the production of pure monomer thermoplasticresins are in some cases synthetically generated or highly purifiedmonomer species. For example, styrene can be generated from ethylbenzene or alpha methyl styrene from cumene. In one embodiment, puremonomer hydrocarbon thermoplastic resins are prepared by cationicpolymerization of styrene-based monomers such as styrene, alpha-methylstyrene, vinyl toluene, and other alkyl substituted styrenes usingFriedel-Crafts polymerization catalysts such as Lewis acids (e.g., borontrifluoride (BF₃), complexes of boron trifluoride, aluminum trichloride(AlCl₃), and alkyl aluminum chlorides). Solid acid catalysts can also beutilized to produce pure monomer thermoplastic resins. The pure monomerthermoplastic resins disclosed herein are non-hydrogenated, partiallyhydrogenated, or fully hydrogenated resins. The term “hydrogenated” asused herein is also indicated alternatively in the shorthand “H2” andwhen H2 is used preceding or following a resin type it is intended toindicate that resin type is hydrogenated or partially hydrogenated, suchas “PMR H2” and “C5 H2” for example. When “H2” is used herein, “H2” ismeant to encompass both fully hydrogenated resin samples and partiallyhydrogenated resin samples. Thus, “H2” refers to the condition in whichthe resin is either fully hydrogenated or at least partiallyhydrogenated. Pure monomer thermoplastic resins are in some instancesobtained as Piccolastic® styrenic hydrocarbon thermoplastic resins,Kristalex® styrenic/alkyl styrenic hydrocarbon thermoplastic resins,Piccotex® alkyl styrenic hydrocarbon thermoplastic resins, and Regalrez®hydrogenated or partially hydrogenated pure monomer thermoplastic resinsfrom Eastman Chemical Company (Kingsport, Tenn., US).

The term “terpene thermoplastic resin” or “polyterpene resin” as usedherein means thermoplastic resins produced from at least one terpenemonomer. For example, α-pinene, β-pinene, d-limonene, and dipentene canbe polymerized in the presence of aluminum chloride to providepolyterpene thermoplastic resins. Other examples of polyterpenethermoplastic resins include Sylvares® TR 1100 and Sylvatraxx® 4125terpene thermoplastic resin (AZ Chem Holdings, LP, Jacksonville, Fla.,US), and Piccolyte® A125 terpene thermoplastic resin (Pinova, Inc.,Brunswick, Ga., US). Terpene thermoplastic resins can also be modifiedwith aromatic compounds. Sylvares® ZT 105LT and Sylvares® ZT 115 LTterpene thermoplastic resins are aromatically modified (Az ChemHoldings, LP, Jacksonville, Fla., US).

It is to be understood that encompassed by the above definitions ofcertain types of thermoplastic resins, such as DCPD, PMR, C5, C9, C5/C9,IC, terpene, and the like, including hydrogenated,partially-hydrogenated, and non-hydrogenated versions of these resins,that these thermoplastic resins include resins of similar typesgenerated by mixing or blending of dissimilar feedstocks to produceheterogeneous mixtures of the feedstocks used to generate thethermoplastic resins. Furthermore, it is to be understood that at leastwith respect to the PMR and terpene thermoplastic resins discussedherein these thermoplastic resins encompass various known derivatives ofsuch thermoplastic resins such as phenol-modified and rosin-modifiedversions of the resins.

“The initial calibration was performed by preparing solutions containingthe individual components in methanol at concentrations ranging from1-5000 parts per million. 10 μL of each solution was analyzed at 190° C.for 10 minutes, and from the resultant calibration curves, a table ofrelative response factors was generated. All subsequent calibrationswere performed with cyclohexane and toluene, and specific componentswere quantified using response factors relative to either cyclohexane ortoluene.”

The term “volatile organic compound” (VOC) as used herein means volatileorganic compounds that are measured according to head space gasspectrometry/mass chromatography (GC/MS). In this method, a headspacesampler is interfaced with a gas chromatograph equipped with a massselective detector. The sample size is 0.1 grams of sample in a 22.5 mlheadspace vial. Sampling conditioning temperatures are 100° C. for 30minutes and 190° C. for 30 minutes. The initial calibration wasperformed by preparing solutions containing the individual components inmethanol at concentrations ranging from 1-5000 parts per million. 10 μLof each solution was analyzed at 190° C. for 10 minutes, and from theresultant calibration curves, a table of relative response factors wasgenerated. All subsequent calibrations were performed with cyclohexaneand toluene, and specific components were quantified using responsefactors relative to either cyclohexane or toluene. Generally, thevolatile organic compounds (VOCs) are compounds having a boiling/elutiontemperature range up to the boiling/elution temperature of compoundshaving 25 carbon atoms. In one embodiment, VOCs in tackifiercompositions and adhesive compositions can include at least one selectedfrom the group consisting of solvent compounds, monomers, comonomers,diluents, catalyst decomposition products, and decomposition products ofthe adhesive, which includes the base polymer, tackifier compositions,and additives.

The term “trace chemicals” refer to any volatile organic compounds thatare of particular interest as odor causing compounds and health relatedconcerns in adhesive formulations. Examples of trace chemicals include,but are not limited to, hexane, methyl chloride, tetrachloroethene,chloroform, trichloroethene, toluene, o, m, p-xylenes, ethylbenzene,styrene, cyclohexane, ethylcyclohexane, indene, vinyl toluene, and alphamethyl styrene.

The term “part by weight” in an adhesive formulation refers to parts ofa component based on 100 parts of the adhesive formulation.

Thermoplastic hydrocarbon resins can be any that is known in the art. Inone embodiment, thermoplastic hydrocarbon resins include, but are notlimited to, PMR, DCPD, C5, C9, C5/C9, terpene, and IC thermoplasticresins, for example, as well as hydrogenated, partially-hydrogenated,and non-hydrogenated versions of these resins, and mixtures thereof.

The polymerization of thermoplastic resins from monomer units istypically performed in organic solvent according to known procedures inthe art. The solvent is then removed by evaporation or other methodafter the polymerization process resulting in the thermoplastichydrocarbon resin. During the evaporation process the solvent isselectively removed, however, some solvent and monomers remain in thethermoplastic hydrocarbon resin.

Improvement of such thermoplastic hydrocarbon resins is often desired toobtain more desirable physical properties in adhesive compositions. Ithas been surprisingly discovered that by removing a percentage of thevolatile organic compounds (VOCs) from the thermoplastic hydrocarbonresin and the addition of an antioxidant composition comprising at leastone primary antioxidant, optionally at least one secondary antioxidant,and at least one hindered amine light stabilizer (HALS) to thethermoplastic hydrocarbon resin, a tackifier composition is producedhaving low odor and low VOCs. This tackifier composition is useful inproducing adhesives for consumer goods having low odor and low VOCs.

Any process known in the art can remove the volatile organic compoundsfrom the thermoplastic hydrocarbon resins. To reduce the amount of VOCsin the thermoplastic hydrocarbon resins, several techniques known in theart are suitable, such as, but not limited to, one or more of: membraneseparation, selective precipitation, selective polymerizationconditions, evaporation and distillation, and preparative gel permeationchromatography.

Membrane separation is commonly employed as a purification technique inthermoplastic resin chemistry. (See, for instance, Bowen et al., Chem.Eng. Res. Des., 76(8):885-893, 1998, and Llosa Tanco et al., Process,4(29):1-21, 2016, herein incorporated by reference to the extent it doesnot contradict the statements in this disclosure). In this method, themembrane is typically a selective barrier that permits the separation ofcertain chemical species in a liquid by a combination of sieving andsorption diffusion mechanism. Membranes can selectively separatecomponents of a liquid composition based on particle size, over a widerange of particle sizes and molecular weights, from large polymeric,i.e. greater than 5,000 g/mol Mn, to low monomolecular materials. Giventhis ability, membrane separation is a suitable technology to remove VOCfractions from thermoplastic hydrocarbon resins of many different types.

Selective precipitation is also suitable for removing VOC fractions fromthermoplastic resins. (See, for example, Niederauer et al.,Bioseparation, Vol. 47, “Advances in BiochemicalEngineering/Biotechnology,” pages 159 to 188, 2006; and Loadman, M. J.R., “Analysis of Rubber and Rubber-Like Polymers,” 4^(th) Ed., SpringerScience and Business Media, B.V., Dordrecht, Netherlands, 1998). Thesolubility in a given solvent depends on its concentration, molecularweight, and the temperature of the solution. Under certain conditions,the thermoplastic hydrocarbon resin with a molecular weight above acertain value is not soluble anymore and precipitates, while the lowmolecular weight species remain soluble. By separating the precipitatefrom the solution by filtration or centrifuging, the VOC fractions canbe removed from thermoplastic hydrocarbon resins.

Another technique commonly used to separate VOCs from thermoplasticresins is preparative gel permeation chromatography, sometimes referredto in the literature as size exclusion chromatography (SEC) or gelpermeation chromatography. (See, for example, Lesec, J., J. LiquidChrom., 8(5):875-923, 2006; and Striegel, A. et al., “ModernSize-Exclusion Liquid Chromatography: Practice of Gel Permeation and GelFiltration Chromatography,” 2^(nd) Ed., John Wiley & Sons, Inc.,Hoboken, N.J., 2009, herein incorporated by reference to the extent itdoes not contradict the statements in this disclosure). This methodologyis successfully applied in the pharmaceutical industry to separate andfractionate mixtures. As applied to thermoplastic resin samples, asolution of the thermoplastic hydrocarbon resin sample is applied to thetop of a gel column. The gel particles have distinct pore sizes of adiameter that is in the same range of the thermoplastic hydrocarbonresin. The low molecular weight fraction of the thermoplastichydrocarbon resin will diffuse deep into the gel particle pores, whilethe larger molecular weight fractions of the thermoplastic hydrocarbonresin can only diffuse a small distance into the gel. As a consequence,the larger sized molecules of the thermoplastic hydrocarbon resin areless retained then the smaller sized molecules, resulting in aseparation between the VOC fraction of the thermoplastic hydrocarbonresin and larger thermoplastic hydrocarbon resin molecules.

Evaporation (wiped film evaporation) and distillation techniques arewidely used to separate VOCs from hydrocarbon thermoplastic resins.(See, for instance, U.S. Pat. No. 4,160,692, herein incorporated byreference to the extent it does not contradict the statements in thisdisclosure). Temperature and pressure levels are selected to achieveadequate separation. In addition, the use of a carrier gas, such as astream of nitrogen, or stream of steam, can help to improve theseparation, but also specific designs of evaporation/distillationhardware, such as thin film evaporators, or distillation columns, canenhance the separation. Evaporation has typically a lower selectivitythan distillation and is used when there is a large difference inboiling point between the distillate and residue.

In one embodiment of the invention, steam stripping is used to removethe VOCs from the thermoplastic hydrocarbon resin. Any process of steamstripping can be utilized. In one example, molten thermoplastichydrocarbon resin and steam are fed to a counter current contactingdevice. Steam and VOCs exit near or at the top as a vapor stream whichis condensed and may be decanted. The remaining molten resin exits nearor at the base as product. The contacting device may have packing, ortrays, or any other type vapor-liquid contacting internals. Thecontactor is operated under vacuum at about 10 to about 1000 mbar, orfrom about 3 to about 100 mbar, or from about 30 to about 50 mbar. Thetemperature in the column is from about 180 to about 280° C., or fromabout 190 to about 260° C., or from about 190 to about 220° C. The steamflow can be from about 0.5% to about 5% or from about 2% to about 5% byweight based on the flowrate of the molten thermoplastic hydrocarbonresin. The temperature, steam flow, and vacuum can all be adjusted toproduce the desired softening point and VOC removal. Higher pressure canrequire more steam and/or higher temperature.

In another embodiment of the invention, a rotary film evaporator isutilized to remove VOCs from the thermoplastic hydrocarbon resin. Thetemperature of the rotary film evaporator is generally less than 240° C.

The antioxidant composition comprises at least one primary antioxidant,optionally at least one secondary antioxidant, and at least one hinderedamine light stabilizer (HALS). The primary antioxidant, secondaryantioxidant, and HALS can be added in portions or all at once to thethermoplastic hydrocarbon resin at any time after the resin ispolymerized or after hydrogenated. The antioxidants can also be addedafter a portion or all of the VOCs are removed. The primary antioxidant,optionally secondary antioxidant, and HALS can be added all at once orin increments.

The primary antioxidant can be any that is known in the art. In oneembodiment, the primary antioxidant is at least one sterically hinderedphenol selected from the group consisting of CI-CXIX:

wherein R=C₈H₁₇ or C₁₈H₃₇

wherein R=C₈H₁₇ or c₁₂H₂₅;

Secondary arylamines, another type of primary antioxidant, are morereactive toward oxygen centered radicals than are hindered phenols.Synergism between secondary arylamines and hindered phenols leads toregeneration of the amine from the reaction with the phenol. An exampleof a secondary arylamine antioxidant isbenzenamine, N-phenyl-, reactionproducts with 2,4,4-trimethylpentene (CAS 68411-46-1), that can beobtained from BASF as Irganox 5057®.

The secondary antioxidant can be any that is known in the art. In oneembodiment, the secondary antioxidant is an organo-phosphite, thioether(or organic sulfide), or hydroxyl-amine.

Examples of organo-phosphite antioxidants include, but are not limitedto, 2, 2′,T-Nitrilo[triethyl-25tris[3,3,5,5-tetra-tert.-butyl-1,1-biphenyl-2,2diyl] phosphite (CAS80410-33-9); Bis(2,4-di-tert.-butyl-6-methylphenyl)-ethyl-phosphite (CAS145650-60-8); Bis-(2,4-ditert.-butylphenol)pentaerythritol diphosphate(CAS 26741-53-7); Tris(2,4-di-tert.butylphenyl) phosphite (CAS31570-04-4); Tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonite (CAS 119345-01-6); andTri-(nonylphenol)-phosphite 30.

These phosphite antioxidants can be obtained as Irgafos® 12, Irgafos®38, Irgafos® 126, Irgafos® 168, Irgafos®, and Irgafos® antioxidants fromBASF.

Examples of thioether antioxidants are Didodecyl-3,3′-thiodipropionate(CAS 123-28-4), 3,3′-Thiodipropionic acid dioctadecylester (CAS693-36-7). These thioether antioxidants can be obtained as Irganox® PS800 and Irgafos® 802 from BASF.

An example of a hydroxyl-amine based antioxidant is oxidizedbis(hydrogenated tallow alkyl) amines (CAS: 143925-92-2) which can beobtained as Irgastab® FS 042 from BASF.

The hindered amine light stabilizer (HALS) can be any that is known inthe art. In one embodiment, the HALs compound is at least one selectedfrom the group consisting of A(1)-A(X):

wherein R=H, CH₃ or OC₈H₁₇

The amount of primary antioxidant can range from about 0.1% to about 1%,from about 0.1% to about 0.9%, from about 0.1% to about 0.8%, from about0.1% to about 0.7%, from about 0.3% to about 0.6% from about 0.3% toabout 0.5% by weight based on the weight of the thermoplastichydrocarbon resin.

The amount of secondary antioxidant can range from about 0.1% to about1%, from about 0.1% to about 0.9%, from about 0.1% to about 0.8%, fromabout 0.1% to about 0.7%, from about 0.3% to about 0.6% from about 0.3%to about 0.5% by weight based on the weight of the thermoplastichydrocarbon resin.

The amount of HALS can range from about 0.05% to about 0.5%, from about0.05% to about 0.45%, from about 0.05% to about 0.4%, from about 0.05%to about 0.35%, from about 0.05% to about 0.3%, from about 0.05% toabout 0.25%, from about 0.05% to about 0.2%, from about 0.05% to about0.15%, from about 0.05% to about 0.1% by weight based on the weight ofthe thermoplastic hydrocarbon resin.

In one embodiment, the antioxidant composition comprises the compoundsshown in Table 1.

TABLE 1 Molec- ular Chemical Type/ Trade Name CAS# Structure weight nameCategory Names Amount Irganox ® 1010 (primary anti- oxidant) 6683-19-8

1178 g/mol Pentaery- thritol tetrakis(3- (3,5-di- tert- butyl-4-hydroxy- phenyl) propionate Primary antioxidant (Sterically) hinderedphenolic antioxidant Irganox ® 1010 (BASF) SONGNOX ® 1010 (Songwon)BNX ® 1010 (Mayzo) From about 0.1% to 1 wt % based on the amount ofthermo- plastic hydro- carbon resin Tinuvin ® 770 (HALS) 52829-07-9

 481 g/mol Bis (2,2,6,6,- tetra- methyl- 4- piperidyl) sebaceateHindered amine light stabilizer (HALS) Hindered amine stabilizer (HALS)Tinuvin ® 770 (BASF) SABO ® STAB UV 70 (Songwon) BLS ® 1770 (Mayzo) Fromabout 0.05% to about 0.5 wt % based on the amount of thermo- plastichydro- carbon resin

In another embodiment, the antioxidant composition comprises thecompounds shown in Table 2.

TABLE 2 Molec- ular Chemical Type/ Trade Name CAS# Structure weight nameCategory Names Amount Irganox ® 1010 (pimary anti- oxidant) 6683- 19-8

1178 g/mol Pentaery- thritol tetrakis(3- (3,5-di- tert- butyl-4-hydroxy- phenyl) propionate Primary antioxidant (Sterically) hinderedphenolic antioxidant Irganox ® 1010 (BASF) SONGNOX ® 1010 (Songwon)BNX ® 1010 (Mayzo) From about 0.1% to 1 wt % based on the amount ofthermo- plastic hydro- carbon resin Irgafos ® 168 (secondary anti-oxidant) 31570- 04-4

  646.9 g/mol Tris(2,4- ditert- butyl- phenyl) phosphite Secondaryantioxidant phosphite processing stabilizer Irgafos ® 168 (BASF)Songnox ® 1680 (Songwon) Benefos ® 1680 (Mayzo) From about 0.1% to 1 wt% based on the amount of thermo- plastic hydro- carbon resin Tinuvin ®770 (HALS) 52829- 07-9

 481 g/mol Bis (2,2,6,6,- tetra- methyl- 4- piperidyl) sebaceateHindered amine light stabilizer (HALS) Hindered amine stabilizer (HALS)Tinuvin ® 770 (BASF) SABO ® STAB UV 70 (Songwon) BLS ® 1770 (Mayzo) Fromabout 0.05% to about 0.5 wt % based on the amount of thermo- plastichydro- carbon resin

The tackifier composition of this invention can be utilized in anyadhesive composition known in the art. Generally, an adhesivecomposition comprises a base polymer and a tackifier composition. Otheradditives to adhesive compositions include, but are not limited to,waxes, oils, plasticizers, and other compounds.

In the composition embodiments described herein, the adhesivecompositions can comprise at least 1, 2, 3, 4, 5, 10, 15, 20, 25, 30,35, 40, 45, 50, 55, or 60 and/or not more than 99, 95, 90, 85, 80, 75,70, or 65 weight percent of at least one tackifier composition based onthe weight of the adhesive composition.

In various embodiments, the adhesive compositions comprise 10, 20, 30,or 40 and/or not more than 90, 80, 70, or 55 weight percent of at leastone base polymer component based on the weight of the adhesivecomposition.

The adhesive compositions disclosed herein, in various embodiments,contain a base polymer, a tackifier composition, and other additivessuch as, but not limited to, oils, waxes, plasticizers, antioxidants,and fillers, depending on the end use application.

Base polymers for adhesive compositions include polyolefins, styreneblock copolymers, ethylene vinyl-acetate polymers, and olefinicpolymers.

Any polyolefins (PO) known in the art for use in adhesives can beutilized in this invention. In one embodiment, the polyolefin can beselected from the group consisting of linear low density polyethylene(LDPE) high density polyethylene (HDPE), atactic polypropylene (PP orAPP), polybutene-1, and oxidized polyethylene). HDPE has higher meltingpoint and better temperature resistance). Atactic polypropylene (PP orAPP), polybutene-1, oxidized polyethylene, etc. can provide very goodadhesion to polypropylene, good moisture barrier, chemical resistanceagainst polar solvents and solutions of acids, bases, and alcohols.Polyolefins have low surface energy and provide good wetting of mostmetals and polymers. Polyolefins made by metallocene catalyzed synthesishave narrow distribution of molecular weight and correspondingly narrowmelting temperature range. PE and APP are usually used on their own orwith just a small amount of tackifiers (usually hydrocarbons) and waxes(usually paraffins or microcrystalline waxes). Polybutene-1 and itscopolymers are soft and flexible, tough, partially crystalline, andslowly crystallizing with long open times. The low temperature ofrecrystallization allows for stress release during formation of thebond.

The styrenic block copolymers (SBC) used in adhesive compositions of thepresent invention is any styrene containing block copolymer or mixturethereof, including modified and/or hydrogenated derivatives thereof.Examples include, but are not limited to, SBS(styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS(styrene-ethylene-butylene-styrene), SEPS(styrene-ethylene/propylene-styrene) block copolymers, SVS(styrene-vinylbutadiene-styrene), SB (styrene-butadiene diblockpolymers), and SI (styrene-isoprene diblock polymers). In embodimentswhen hot melt adhesives are produced, particular useful styrenic blockcopolymers are S-I-S block copolymers and S-B-S block copolymers.However, the present invention is not limited to these types of styreniccopolymers. Commercially available SBC polymers include, for example,those polymers manufactured under the trademarks “Kraton®” from Kraton,“Stereon®” from Firestone, “Europrene®” from Polimeri Europa (FormerPolimeri Europa (EniChem), etc. Other suppliers are GoodYear, Lanxess,Zeon, and JSR.

Styrene block copolymers (SBC), also called styrene copolymer adhesivesand rubber-based adhesives, have good low-temperature flexibility, highelongation, and high heat resistance. They are frequently used inpressure-sensitive adhesive applications, where the composition retainstack even when solidified; however non-pressure-sensitive formulationsare also used. They usually have A-B-A structure, with an elastic rubbersegment between two rigid plastic endblocks. The A-B-A structurepromotes a phase separation of the polymer, binding together the endblocks, with the central elastic parts acting as cross-links; thus SBCsdo not require additional cross-linking. Styrene-butadiene-styrene (SBS)polymers are used in high-strength PSA applications.Styrene-isoprene-styrene (SIS) polymers are used in low-viscosityhigh-tack PSA applications. Styrene-ethylene/butylene-styrene (SEBS) areused in low self-adhering nonwoven applications.

Olefinic polymers can also be used in adhesives formulations, includinghot melt adhesives. Olefinic polymers include ethylene vinyl acetate(EVA), amorphous polyolefins, metallocene polyolefins, and olefin blockcopolymers.

Ethylene vinyl-acetate (EVA) is a solid, transparent, flexible ethylenevinyl aetate copolymer. It is normally categorized by percent vinylacetate (VA) content and melt flow rate (MFR) or melt index (MI). Mostcommonly used EVAs contain between about 19% and about 28% VA by weight.The MI values can range from about 3 to about 2500. EVA polymers aresold under trade names Elvax® from DOW Chemical (former DuPont), Ateva®from Celanese corporation, Nipoflex® from Tosoh, and Greenflex® fromDistrupol, etc.

Amorphous polyolefin (APO) polymers are compatible with many solvents,tackifiers, waxes, and polymers; they find wide use in many adhesiveapplications. APO hot melt adhesives have good fuel and acid resistance,moderate heat resistance, are tacky, soft and flexible, have goodadhesion and longer open times than crystalline polyolefins. APOs tendto have lower melt viscosity, better adhesion, longer open times andslow set times than comparable EVAs. Some APOs can be used alone, butoften they are compounded with tackifiers, waxes, and plasticizers(e.g., mineral oil, polybutene oil). Examples of APOs include, but arenot limited to, amorphous (atactic) propylene (APP), amorphouspropylene/ethylene (APE), amorphous propylene/butene (APB), amorphouspropylene/hexene (APH), amorphous propylene/ethylene/butene.

Amorphous polypropylene (APP) was first produced as a by-product ofcrystalline polypropylene and was obtained by solvent extraction. ThisAPP polymer could be combined with various tackifiers, plasticizers,waxes, etc. to produce an adhesive that can be used for diaperconstruction, for example. Amorphous poly alpha olefins (APAOs) wereproduced on purpose using Ziegler-Natta catalysis and can be made usinga variety of monomers, including, but not limited to, propylene,ethylene and butene. Various copolymers and terpolymers are produced bya number of manufacturers. They include Evonik Industries, who producethe Vestoplast® polymers; REXtac, LLC, who produces the Rextac® RT rangeof materials and Eastman Chemical, manufacturers of the Eastoflex® lineof polymers. They are all characterized by having a low degree ofcrystallinity as measured by DSC. As commercially produced, they arerandom polymers having broad molecular weight distributions.

Metallocene polyolefins, also called polyolefin elastomers, can also beused as a base polymer in adhesive compositions. These polymers are madewith metallocene catalysis technology. Polymers can be made usingcomonomer, such as butene-1 and octene-1, to produce polymers with verylow levels of crystallinity (about 16˜about 18%) and density of about0.87 g/cm³. Examples of these metallocene polymers include Affinity® andEngage® polymers from Dow Chemical Company, L-MODU® from Idemitsu(Japan). Metallocene polyolefin polymers are also supplied by severalother companies, such as ExxonMobil Corporation (U.S.), LyondellBaselIndustries Holdings B.V. (Netherlands), Chevron Phillips ChemicalCompany LLC (U.S.), Total SA (France), SABIC (Saudi Arabia), JapanPolychem Corporation Ltd, Braskem AG (Brazil), LG Chem Ltd. (SouthKorea), and others.

Olefin block copolymers (OBC) is a new class of polyolefin polymerproduced using a chain shuttling catalysis technology that produces alinear block structure of the monomers rather than a random polymerproduced by Ziegler-Natta or traditional metallocene technology. OBCsare manufactured by Dow Chemical under the trade name of Infuse®. OBCsconsist of crystallizable ethylene-octene blocks (hard) and amorphousethylene-octene blocks (soft). The block structures give the polymermuch better elevated temperature resistance and elasticity compared to atypical metallocene random polymer of similar density. While some of thegrades of Infuse® have low heat of fusion (approximately 20 Joules/gram)they would not be considered to be amorphous poly-alpha-olefins becausethe polymer architecture is completely different (i.e. block vs. random)and is specifically produced to have crystalline regions. Not only arethey different on a structural basis, they are very different from aphysical property standpoint with the OBCs having better elasticrecovery, compression set and elevated temperature resistance. As such,they are sold into different markets for different end uses and are notconsidered equivalent for one another.

Exemplary base polymer components of the disclosed compositions include,but are not limited to, ethylene vinyl acetate copolymer, ethylenen-butyl acrylate copolymer, ethylene methyl acrylate copolymer,polyester, neoprene, acrylics, urethane, poly(acrylate), ethyleneacrylic acid copolymer, polyether ether ketone, polyamide, styrenicblock copolymers, random styrenic copolymers, hydrogenated styrenicblock copolymers, styrene butadiene copolymers, natural rubber,polyisoprene, polyisobutylene, atactic polypropylene, polyethyleneincluding atactic polypropylene, ethylene-propylene polymers,propylene-hexene polymers, ethylene-butene polymers, ethylene octenepolymers, propylene-butene polymers, propylene-octene polymers,metallocene-catalyzed polypropylene polymers, metallocene-catalyzedpolyethylene polymers, ethylene-propylene-butylene terpolymers,copolymers produced from propylene, ethylene, and various C₄-C₁₀alpha-olefin monomers, polypropylene polymers, functional polymers suchas maleated polyolefins, butyl rubber, polyester copolymers, copolyesterpolymers, isoprene, the terpolymer formed from the monomers ethylene,propylene, and a bicyclic olefin (known as “EPDM”), isoprene-based blockcopolymers, butadiene-based block copolymers, acrylate copolymers suchas ethylene acrylic acid copolymer, butadiene acrylonitrile rubber,and/or polyvinyl acetate.

In another embodiment, adhesive formulations utilize polymers with lowamounts of VOCs. Polyolefin polymers can have low VOC content and canassist in producing adhesives with low VOC and odor.

Waxes can also be contained in adhesive compositions. Any wax known inthe art for use in adhesives can be utilized. Waxes, e.g.microcrystalline waxes, fatty amide waxes or oxidized Fischer-Tropschwaxes, increase the setting rate. One of the key components of adhesiveformulations, waxes lower the melt viscosity and can improve bondstrength and temperature resistance.

Various waxes also may be present in the adhesive composition of thepresent invention in amounts of about 0 to about 50 parts by weightbased on the weight of the adhesive composition.

Low molecular weight polyethylene or polypropylene waxes, other thanthose polymerized by metallocene catalysts, are low molecular weightpolymers made by direct polymerization of ethylene and propylene underconditions whereby molecular weight is controlled. These polymer waxesare available from a number of sources; polymer waxes useful in the hotmelt adhesive compositions of the invention include Marcus® 200, 300,500, 4040, and 2000 waxes from Marcus Oil and Chemical Corp. of Houston,Tex.; BARECO® C-4040 wax from Baker Hughes of Barnsdall, Okla.; andEPOLENE® C-10, C-18, and N-15 from Westlake Chemical Corp. of Houston,Tex.

Petroleum waxes, such as paraffin wax and microcrystalline wax, can alsobe utilized. Paraffin waxes are hydrocarbon mixtures with the generalformula C_(n)H_(2n+2) wherein 20≤n≤40. Straight chain saturatedhydrocarbons are the predominant functionality, though there aretypically small amounts of unsaturated and/or branched hydrocarbons.Paraffin waxes are available from a broad range of sources includingconsumer sources.

Synthetic waxes made by polymerizing carbon monoxide and hydrogen, suchas Fischer-Tropsch wax, can also be used in adhesive compositions.Fischer-Tropsch waxes are synthetic waxes produced by theFischer-Tropsch process, which is a method for the synthesis ofhydrocarbons and other aliphatic compounds from a mixture of hydrogenand carbon monoxide in the presence of a catalyst. The gaseous mixturecan be obtained by coal gasification or natural gas reforming. The waxesare fractionated by chain length and are characterized as substantiallysaturated and linear aliphatic chains free of aromatic, sulfurous, andnitrogenous content. Fischer-Tropsch waxes are available from a numberof sources. Some Fischer-Tropsch waxes useful in the hot melt adhesivecompositions of the invention include those marketed under the tradename SASOLWAX®, for example SASOLWAX® C 80 and SASOLWAX® H 1, availablefrom Sasol Wax North America Corp. of Hayward, Calif.; those marketedunder the trade name VESTOWAX® available from Evonik Degussa of Essen,Germany; and those marketed under the trade name ACUMIST® available fromHoneywell International Inc. of Morristown, N.J.

A product modified from above mentioned waxes can also be utilized. Forexample, maleic anhydride modified waxes from Honeywell: A-C 573A, A-C573P, can be used.

As noted above, in some embodiments, the described compositions compriseadditives particularly suitable for a specific end-use application. Forexample, if the adhesive is intended to serve as a hot melt packagingadhesive, as noted above, then in this embodiment, the composition willfurther comprise a wax. In some embodiments, the adhesive compositioncomprises at least 1, 2, 5, 8, or 10 and/or not more than 40, 30, 25, or20 weight percent of at least one wax. In another embodiment, thecompositions described herein comprise about 1 to about 40, about 5 toabout 30, about 8 to about 25, or about 10 to about 20 weight percent ofat least one wax. In such embodiments, a wax is included in thecomposition in an amount of between about 10 and about 100 parts wax per100 parts of the adhesive composition.

In one embodiment of the invention, waxes containing low amounts of VOCsare utilized in the adhesive formulations. In one embodiment of theinvention, the wax contains less than 0.5 ppm VOC as measured byheadspace MS/GC analysis as specified in this disclosure.

Other additional stabilizers or antioxidants known in the art may alsobe present in the adhesive composition. In one embodiment of theinvention, the additional antioxidant is a sterically hindered phenolcompounds, such as Irganox® 1010 antioxidant obtained from BASF.

In other embodiments, the tackifier compositions that incorporate one ormore thermoplastic hydrocarbon resin can further comprise at least about0.1, 0.5, 1, 2, or about 3 and/or not more than about 20, 10, 8, orabout 5 weight percent of at least one other antioxidant. Anyantioxidant known to a person of ordinary skill in the art may be usedin the adhesion compositions disclosed herein. Non-limiting examples ofsuitable other antioxidants include amine-based antioxidants such asalkyl diphenyl amines, phenyl-naphthylamine, alkyl or aralkylsubstituted phenyl-naphthylamine, alkylated p-phenylene diamines,tetramethyl-diaminodiphenylamine and the like; and hindered phenolcompounds such as 2,6-di-t-butyl-4-methylphenol;1,3,5-trimethyl-2,4,6-tris(3′,5′-di-t-butyl-4′-hydroxybenzyl)benzene;tetra kis [(methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane,such as IRGANOX® 1010 (BASF Corp., LA, US);octadecyl-3,5-di-t-butyl-4-hydroxycinnamate, such as IRGANOX® 1076 (BASFCorp., LA, US) and combinations thereof. Where used, the amount of theother antioxidant in the composition can be from about greater than 0 toabout 1 wt %, from about 0.05 to about 0.75 wt %, or from about 0.1 toabout 0.5 wt % of the total weight of the adhesive composition. Inanother such embodiment, the adhesive compositions comprise about 0.1 toabout 20, about 1 to about 10, about 2 to about 8, or about 3 to about 5weight percent of at least one other antioxidant.

Variety of fillers can be used in hot melt adhesive formulations.Fillers can have a deep effect on cost, compounding characteristics, andfinal adhesive properties. Any filler known in the art to be used inadhesive compositions can be utilized. The commonly used fillers includeincluding calcium carbonate, carbon black, titanium oxide, zinc oxide,alumina trihydrate, barium sulfate, silica and kaolin clay. In anotherembodiment of the described compositions, the compositions comprise atleast about 10, 20, 30, or about 40 and/or not more than about 90, 80,70, or about 55 weight percent of at least one filler. In a furtherembodiment, the compositions comprise about 1 to about 90, about 20 toabout 80, about 30 to about 70, or about 40 to about 55 weight percentof at least one filler.

Plasticizers can also be contained in adhesive compositions.Plasticizers can be any that is known in the art. Plasticizers include,but are not limited to, benzoates, such as, 1,4-cyclohexane dimethanoldibenzoate, glyceryl tribenzoate, or pentaerythritol tetrabenzoate,phthalates, oils, polyisobutylene, chlorinated paraffins, and the like.

Various plasticizing oils or extending oils also may be present in theadhesive composition of the present invention in amounts of about 0 toabout 50 parts by weight. Commercially available plasticizing oilsinclude, for example, those manufactured under the trademarks,“Shellflex®”, “Ondina®” (both produced by Shell Chemical Company),“Primol®”, “Flexon®” (Exxon Chemical Company), Hydrobrite® fromSonneborn or “Kaydol®” (Witco Chemical Company).

The plasticizing oils include not only the usual plasticizing oils, butalso naphthenic/paraffinic oils, olefin oligomers and low molecularweight polymers, as well as vegetable and animal oil and derivatives ofsuch oils. Plasticizer oils also include liquid resins as well asmixtures thereof with olefin oligomers and/or low molecular weightpolymers. The examples of common plasticizing oils are Kaydol whitemineral oil, Tufflo® mineral oil, Shellflex® 371 N, Shelflex® 451,Calsol® 5550 Hydrobrite® 380 PO White Mineral Oil.

Liquid resin of use in this invention may be any resin having a R&Bsoftening point below the R&B softening point of the tackifying resin ofthis invention. Preferably the liquid resin should have a R&B softeningpoint below 50° C., most preferably, the liquid resin has e R&Bsoftening point below ambient temperature (21° C.).

The oligomers may be polypropylenes, polybutenes, hydrogenatedpolyisoprene, hydrogenated butadiene, or the like having averagemolecular weights between about 350 Dalton and about 10,000 Dalton.Commercially available plasticizing oligomers include, for example,those manufactured under the trademarks, “Napvis®”, “Hyvis®”, which areboth manufactured by BP Chemical Company, or “Amoco Polybutenes®”,manufactured by the Amoco Chemical Specialities Company. Suitablevegetable and animal oils include glycerol esters of the usual fattyacids and polymerization products thereof.

In pressure sensitive adhesive (PSA) composition embodiments, such asadhesives used in tapes, mastics, and labels, and in nonwovenapplications of the described adhesive compositions, various oils areadded to the adhesive compositions. In one embodiment, the adhesivecomposition comprises at least about 1, 2, 5, 8, or about 10 and/or notmore than about 40, 30, 25, or about 20 weight percent of at least oneprocessing oil. In another embodiment of pressure sensitive adhesivecompositions, the adhesive compositions comprise about 2 to about 40,about 5 to about 30, about 8 to about 25, or about 10 to about 20 weightpercent of at least one processing oil. Processing oils include, but arenot limited to, mineral oils, naphthenic oils, paraffinic oils, aromaticoils, castor oils, rape seed oil, triglyceride oils, and combinationsthereof. Processing oils also include extender oils that are commonlyused in various pressure-sensitive adhesive compositions. In anotherembodiment, the described adhesive composition comprises no processingoils.

In one embodiment of the invention, adhesive compositions utilizeplasticizer oils having low VOC content. In some adhesive compositions,plasticizer oils having less than 0.5 ppm VOC based on headspace MS/GCanalysis as defined in this disclosure.

In another embodiment of the compositions, one or more plasticizers areadded to the adhesive compositions, such as, but not limited to,phthalate esters such as, for example, dibutyl phthalate and dioctylphthalate, benzoates, terephthalates, and chlorinated paraffins. In oneembodiment, the described adhesive compositions comprise at least about0.5, 1, 2, or about 3 and/or not more than about 20, 10, 8, or about 5weight percent of at least one plasticizer. In another embodiment, theadhesive compositions comprise about 0.5 to about 20, about 1 to about10, about 2 to about 8, or about 3 to about 5 weight percent of at leastone plasticizer. Other exemplary plasticizers include Benzoflex™ andEastman 168™ (Eastman Chemical Company, Kingsport, Tenn., US).

In some embodiments, the compositions described herein include otherconventional plastic additives in an amount that is sufficient to obtaina desired processing or performance property for the adhesive. Theamount should not be wasteful of the additive nor detrimental to theprocessing or performance of the adhesive. Those skilled in the art ofthermoplastics compounding, without undue experimentation but withreference to such treatises as Plastics Additives Database (2004) fromPlastics Design Library (www.elsevier.com) can select from manydifferent types of additives for inclusion into the compounds describedherein. Non-limiting examples of optional additives include adhesionpromoters; biocides (antibacterials, fungicides, and mildewcides),anti-fogging agents; anti-static agents; bonding, blowing and foamingagents; dispersants; fillers and extenders; fire and flame retardantsand smoke suppressants; impact modifiers; initiators; lubricants; micas;pigments, colorants and dyes; oils and plasticizers; processing aids;release agents; silanes, titanates and zirconates; slip andanti-blocking agents; stabilizers (for example, Irganox® 1010 andIrganox® 1076, BASF Corporation, LA, US); stearates; ultraviolet lightabsorbers; viscosity regulators; waxes; and combinations thereof.Antioxidants are particularly useful for these compounds to provideadditional durability.

Such compositions are manufactured in one embodiment by blending thebase polymer and tackifier composition to form the adhesive. That is,the adhesive compositions described herein are in one embodimentprepared by combining the base polymer, tackifier composition and theadditives using conventional techniques and equipment. As a non-limitingexemplary embodiment, the components of the compositions describedherein are blended in a mixer such as a Sigma blade mixer, aplasticorder, a Brabender mixer, a twin-screw extruder, and/or an in-canblend can (pint-cans). In another embodiment, the compositions areshaped into a desired form, such as a tape or sheet, by an appropriatetechnique including, for example, extrusion, compression molding,calendaring, or roll coating techniques (gravure, reverse roll, and thelike). In some embodiments, the compositions described herein areapplied using curtain coating, slot-die coating, or sprayed throughdifferent nozzle configurations at different speeds using typicalapplication equipment.

In another embodiment, the compositions described herein are applied toa substrate by melting the composition and then using conventional hotmelt adhesive application equipment recognized in the art to coat thesubstrate with the composition. Substrates include, for example,textile, fabric, paper, glass, plastic, and metal materials. Typically,about 0.1 to about 100 g/m² of adhesive composition is applied to asubstrate.

In one embodiment of this invention, a hot melt adhesive is providedcomprising at least one base polymer and at least one tackifiercomposition; wherein the tackifier composition comprises at least onethermoplastic hydrocarbon resin and an antioxidant composition; whereinat least a portion of the volatile organic compounds in thethermoplastic hydrocarbon resin has been removed; wherein theantioxidant composition comprises at least one primary antioxidant,optionally at least one secondary antioxidant, and at least one HALS;and wherein the levels of individual volatile organic compounds ofinterest in the tackifier composition are less than about 0.5 ppm asmeasured by GC/MS headspace analysis as described in this disclosure.The hot melt adhesive can further comprise at least one selected fromthe group consisting of at least one oil, at least one wax, and at leastone filler. The hot melt adhesive can also contain any additionalantioxidant or stabilizer known in the art.

In an embodiment of the invention, a low odor and low VOC hot meltadhesive is provided. The hot melt adhesive composition comprises:

-   -   (a) About 5 parts to about 90 parts by weight of at least one        base polymer;    -   (b) About 5 parts to about 90 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least one thermoplastic hydrocarbon resin and an        antioxidant composition; wherein a portion of the volatile        organic compounds in the thermoplastic hydrocarbon resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) 0 to about 50 parts by weight of at least one plasticizer;    -   (d) 0 to about 50 parts by weight of at least one wax;    -   (e) 0 to about 1 part by weight of at least one additional        antioxidant; and    -   (f) 0 to about 80 parts by weight of at least one filler.

In an embodiment of the invention, a low odor and low VOC packagingadhesive composition is provided. The packaging hot melt adhesivecomposition comprises:

-   -   (a) about 50 to about 90 parts by weight of at least one EVA        polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifer composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure; and    -   (c) 0 to about 1 part by weight of an additional antioxidant.

In an embodiment of the invention, a low odor and low VOC packagingadhesive is provided. The packaging hot melt adhesive comprises:

-   -   (a) about 10 to about 50 parts by weight of at least one EVA        polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifer composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) about 10 to about 50 parts by weight of at least one wax;        and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC packagingadhesive is provided. The packaging hot melt adhesive comprises:

-   -   (a) about 30 to about 80 parts by weight of at least one EVA        polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifer composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure; and    -   (c) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC packagingadhesive is provided. The packaging hot melt adhesive comprises:

-   -   (a) about 20 to about 90 parts by weight of at least one        metallocene polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifer composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) 0 to about 40 parts by weight of at least one plasticizing        oil;    -   (d) 0 to about 40 parts by weight of at least one wax; and    -   (e) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC packagingadhesive is provided. The packaging hot melt adhesive comprises:

-   -   (a) about 10 to about 50 parts by weight of at least one OBC        polymer;    -   (b) about 30 to about 80 parts by weight of at least one        tackifier compositions; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) 0 to about 40 parts by weight of at least one oil;    -   (d) 0 to about 20 parts by weight of at least one wax; and    -   (e) 0 to about 1 part by weight of at least one antioxidant.

In an embodiment of the invention, a low odor and low VOC packagingadhesive is provided. The packaging hot melt adhesive comprises:

-   -   (a) about 40 to about 90 parts by weight of at least one APAO        polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) 0 to about 20 parts by weight of at least one oil;    -   (d) 0 to about 20 parts by weight of at least one wax; and    -   (e) about 0.2 to about 1 part by weight of at least one        additional antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 10 to about 40 parts by weight of at least one SBC        copolymer;    -   (b) about 20 to about 80 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least one fully hydrogenated or partially        hydrogenated C9 resin and an antioxidant composition; wherein a        portion of the volatile organic compounds in the C9 resin has        been removed; wherein the antioxidant composition comprises at        least one primary antioxidant, optionally at least one secondary        antioxidant, and at least one HALS; and wherein the levels of        individual volatile organic compounds of interest in the        tackifier composition are less than about 0.5 ppm as measured by        GC/MS headspace analysis as described in this disclosure;    -   (c) 0 to about 40 parts by weight of at least one oil; and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive composition is provided. The hygiene hot melt adhesivecomposition comprises:

-   -   (a) about 10 to about 30 parts by weight of at least one SBC        copolymer;    -   (b) about 50 to about 70 parts by weight of a tackifier        composition; wherein the tackifier composition comprises at        least thermoplastic hydrocarbon resin; wherein a portion of the        volatile organic compounds in the thermoplastic hydrocarbon        resin has been removed; wherein the antioxidant composition        comprises at least one primary antioxidant, optionally at least        one secondary antioxidant, and at least one HALS; and wherein        the levels of individual volatile organic compounds of interest        in the tackifier composition are less than about 0.5 ppm as        measured by GC/MS headspace analysis as described in this        disclosure;    -   (c) about 10 to about 30 parts by weight of at least one oil;        and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 15 to about 25 parts by weight of at least one SBC        copolymer;    -   (b) about 55 to about 65 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; and wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this disclosure;    -   (c) about 15 to about 25 parts by weight of at least one oil;        and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 20 to about 70 parts by weight of at least one SBC        copolymer;    -   (b) about 20 to about 80 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this;    -   (c) 0 to about 40 parts by weight of at least one oil; and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 30 to about 50 parts by weight of at least one SBC        copolymer;    -   (b) about 30 to about 50 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; and wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this disclosure;    -   (c) about 10 to about 30 parts by weight of at least one oil;        and    -   (d) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 20 to about 90 parts by weight of at least one        metallocene polymer;    -   (b) about 10 to about 50 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; and wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this disclosure;    -   (c) 0 to about 40 parts by weight of at least one oil;    -   (d) 0 about 40 parts by weight of at least one wax; and    -   (e) 0 to 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) about 10 to about 50 parts by weight of an OBC polymer;    -   (b) about 30 to about 80 parts by weight of at least one        tackifier composition; wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; and wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this disclosure;    -   (c) 0 to about 40 parts by weight of at least one oil;    -   (d) 0 to about 20 parts by weight of at least one wax; and    -   (e) 0 to about 1 part by weight of at least one additional        antioxidant.

In an embodiment of the invention, a low odor and low VOC hygieneadhesive is provided. The hygiene hot melt adhesive comprises:

-   -   (a) 40˜90 parts by weight of at least one APAO polymer;    -   (b) 10˜50 parts by weight of wherein the tackifier composition        comprises at least thermoplastic hydrocarbon resin; wherein a        portion of the volatile organic compounds in the thermoplastic        hydrocarbon resin has been removed; wherein the antioxidant        composition comprises at least one primary antioxidant,        optionally at least one secondary antioxidant, and at least one        HALS; and wherein the levels of individual volatile organic        compounds of interest in the tackifier composition are less than        about 0.5 ppm as measured by GC/MS headspace analysis as        described in this disclosure;    -   (c) 0 to about 20 parts by weight of at least one oil;    -   (d) 0 to about 20 parts by weight of at least one wax; and    -   (e) 0 to about 1 part by weight of at least one additional        antioxidant.

In another embodiment of the invention, a product assembly hot meltadhesive composition is provided. Product assembly adhesives areutilized to in the automobile industry, woodworking industries, andother applications. The product assembly hot melt adhesive compositioncomprises at least one base polymer, at least one tackifier composition,optionally at least one plasticizing oil, optionally at least one wax,optionally at least one filler, and optionally at least one additionalantioxidant; wherein the tackifier composition comprises at least onethermoplastic hydrocarbon resin and an antioxidant composition; whereina portion of the volatile organic compounds in the thermoplastichydrocarbon resin has been removed; wherein the antioxidant compositioncomprises at least one primary antioxidant, optionally at least onesecondary antioxidant, and at least one HALS; and wherein the levels ofindividual volatile organic compounds of interest in the tackifiercomposition are less than about 0.5 ppm as measured by GC/MS headspaceanalysis as described in this disclosure.

In another embodiment of the invention, the product assembly adhesivecomposition is provided comprising: a) about 5 parts to about 90 partsby weight of a base polymer; b) about 5 parts to about 90 parts byweight of at least one tackifier composition; wherein the tackifiercomposition comprises at least one thermoplastic hydrocarbon resin andan antioxidant composition; wherein a portion of the volatile organiccompounds in the thermoplastic hydrocarbon resin has been removed;wherein the antioxidant composition comprises at least one primaryantioxidant, optionally at least one secondary antioxidant, and at leastone HALS; and wherein the levels of individual volatile organiccompounds of interest in the tackifier composition are less than about0.5 ppm as measured by GC/MS headspace analysis as described in thisdisclosure; c) 0 to about 50 parts by weight of at least one plasticizeroil, d) 0 to about 50 parts by weight of at least one wax, e) 0 to about1 part by weight of at least one additional antioxidant; f) 0 to about80 parts by weight of at least one organic or inorganic filler. Thetackifier composition was previously described in this disclosure. Thethermoplastic hydrocarbon resin can have a Rolling Ball softening pointbetween about 70° C. and about 150° C.

In another embodiment of the invention, the product assembly adhesivecomposition is provided comprising: a) about 50 parts to about 90 partsby weight of at least one amorphous polyolefin; b) about 5 parts toabout 90 parts by weight of at least one tackifier composition whereinthe tackifier composition comprises at least one thermoplastichydrocarbon resin and an antioxidant composition; wherein a portion ofthe volatile organic compounds in the thermoplastic hydrocarbon resinhas been removed; wherein the antioxidant composition comprises at leastone primary antioxidant, optionally at least one secondary antioxidant,and at least one HALS; and wherein the levels of individual volatileorganic compounds of interest in the tackifier composition are less thanabout 0.5 ppm as measured by GC/MS headspace analysis as described inthis disclosure; c) 0 to about 50 parts by weight of at least oneplasticizer oil, d) 0 to about 50 parts by weight of at least one wax,e) 0 to about 1 part by weight of at least one additional antioxidant;f) 0 to about 80 parts by weight of at least one organic or inorganicfiller. The tackifier composition was previously described in thisdisclosure. The thermoplastic hydrocarbon resin can have a Rolling Ballsoftening point between about 70° C. and about 150° C.

In another embodiment of the invention, the product assembly adhesivecomposition is provided comprising: a) about 50 parts to about 90 partsby weight of at least one amorphous polyolefin; b) about 5 parts toabout 90 parts by weight of at least one tackifier composition whereinthe tackifier composition comprises at least one thermoplastichydrocarbon resin and an antioxidant composition; wherein a portion ofthe volatile organic compounds in the thermoplastic hydrocarbon resinhas been removed; wherein the antioxidant composition comprises at leastone primary antioxidant, optionally at least one secondary antioxidant,and at least one HALS; and wherein the levels of individual volatileorganic compounds of interest in the tackifier composition are less thanabout 0.5 ppm as measured by GC/MS headspace analysis as described inthis disclosure; c) 0 to about 50 parts by weight of at least oneplasticizer oil, d) 0 to about 50 parts by weight of at least one wax,e) 0 to about 1 part by weight of at least one additional antioxidant;f) 0 to about 80 parts by weight of at least one organic or inorganicfiller. The tackifier composition was previously described in thisdisclosure. The thermoplastic hydrocarbon resin can have a Rolling Ballsoftening point between about 70° C. and about 150° C.

In another embodiment of the invention, the automotive assembly adhesivecomposition is provided comprising: a) about 40 parts to about 90 partsby weight of at least one amorphous polyolefin; b) about 10 parts toabout 50 parts by weight of at least one tackifier composition, whereinthe tackifier composition comprises at least one thermoplastichydrocarbon resin and an antioxidant composition; wherein a portion ofthe volatile organic compounds in the thermoplastic hydrocarbon resinhas been removed; wherein the antioxidant composition comprises at leastone primary antioxidant, optionally at least one secondary antioxidant,and at least one HALS; and wherein the levels of individual volatileorganic compounds of interest in the tackifier composition are less thanabout 0.5 ppm as measured by GC/MS headspace analysis as described inthis disclosure and wherein the thermoplastic hydrocarbon resin is afully hydrogenated or partially hydrogenated C9; c) 0 to about 50 partsby weight of at least one plasticizer oil, d) 0 to about 50 parts byweight of at least one wax, e) 0 to about 1 part by weight of at leastone additional antioxidant; f) 0 to about 80 parts by weight of at leastone organic or inorganic filler. The tackifier composition waspreviously described in this disclosure. The thermoplastic hydrocarbonresin can have a Rolling Ball softening point between about 70° C. andabout 150° C.

The invention has been described in detail with particular reference topreferred embodiments thereof, but it will be understood that variationsand modifications can be affected within the spirit and scope of theinvention.

EXAMPLES

This invention can be further illustrated by the following examples ofpreferred embodiments thereof, although it will be understood that theseexamples are included merely for purposes of illustration and are notintended to limit the scope of the invention unless otherwisespecifically indicated.

Test Methods

Volatile organic compounds were measured according to head space gasspectrometry/mass chromatography (GC/MS). In this method, a headspacesampler is interfaced with a gas chromatograph equipped with a massselective detector. The sample size is 0.1 grams of sample in a 22.5 mlheadspace vial. Sampling conditioning temperatures are 100° C. for 30minutes and 190° C. for 30 minutes. The initial calibration wasperformed by preparing solutions containing the individual components inmethanol at concentrations ranging from 1-5000 parts per million. 10 μLof each solution was analyzed at 190° C. for 10 minutes, and from theresultant calibration curves, a table of relative response factors wasgenerated. All subsequent calibrations were performed with cyclohexaneand toluene, and specific components were quantified using responsefactors relative to either cyclohexane or toluene.

Example 1

VOC levels were determined for various commercial thermoplastichydrocarbon resins as shown in the comparative examples in Table 3 aswell as various inventive tackifier compositions comprising at least onethermoplastic hydrocarbon resin and the inventive antioxidant blends asshown in Table 4. The VOC levels were determined using the headspaceMS/GC method described above at 190 C.° for 30 minutes.

TABLE 3 Comparative Samples Samples Comparative 1 Comparative 2Comparative 3 Comparative 4 Comparative 5 Comparative 6 Stripping No YesNo No No No Pentaerythritol tetrakis(3- — — 0.90% 0.30% 0.30% 0.62%(3,5-di-tert-butyl-4- hydroxyphenyl)propionate Tris(2,4-ditert- — — — —— 0.30% butylphenyl)phosphite Bis(2,2,6,6,-tetramethyl-4- — — 0.10% — —0.08% piperidyl)sebaceate C₉-Partially C₉-Partially C₉-PartiallyC₉-Partially C₉-Fully C₉-Partially hydrogenated hydrogenatedhydrogenated hydrogenated hydrogenated hydrogenated Methylene ChlorideND ND ND ND ND ND Hexane <0.2 ND ND ND ND ND Chloroform ND ND ND ND NDND Cyclohexane 30.3 20.2 0.3 7.6 1.5 0.2 Toluene 9.4 5.1 0.7 3.5 0.2 2.4Ethylcyclohexane 12.3 7.9 <0.2 3.7 0.8 <0.2 Ethylbenzene 8.7 5.6 0.9 2.2ND 0.4 P-Xylene 2.5 1.4 0.37 ND ND 0.2 O-Xylene ND 0.6 <0.2 ND ND <0.2M-Xylene ND ND ND ND ND ND Styrene 30.2 20.0 3.52 8.1 0.6 1.9 a-MethylStyrene 30.3 20.1 0.5 7.0 ND 0.3 Vinyl Toluene 13.9 8.5 1.03 2.5 0.3 0.9Indene 123.2 89.8 13.54 17.2 2.7 12.7 Tetrachloroethene ND ND ND ND NDND Trichloroethene ND ND ND ND ND ND Total 260.8 179.3 20.9 51.8 6.218.8 Volatile organic compounds were measured according to head spacegas spectrometry/mass chromatography (GC-MS) In this method a headspacesampler is interfaced with a gas chromatograph equipped with a massselective detector. The sample size is 0.1 grams of sample in a 22.5 mlheadspace vial Sampling conditioning temperature is 190° C. for 30minutes The detection limit for the components in the hot melt adhesivesis 0.2 ppm ND means not detectable.

TABLE 4 Inventive Samples Inven- Inven- Inven- Inven- Samples tive 1tive 2 tive 3 tive 4 Stripping Yes Yes Yes Yes Pentaerythritoltetrakis(3-    0.90% 0.62% 0.62% 0.62% (3,5-di-tert-butyl-4-hydroxyphenyl)propionate Tris(2,4-ditert- — 0.30% 0.30% 0.30%butylphenyl)phosphite Bis(2,2,6,6,-tetramethyl-    0.10% 0.08% 0.08%0.08% 4-piperidyl)sebaceate C₉- C9- C9- C9- Partially PartiallyPartially Fully hydro- hydro- hydro- hydro- genated genated genatedgenated Methylene Chloride ND ND ND ND Hexane ND ND ND ND Chloroform NDND ND ND Cyclohexane <0.2  ND ND ND Toluene <0.2  ND ND NDEthylcyclohexane ND ND ND ND Ethylbenzene <0.2  ND ND ND P-Xylene ND NDND ND O-Xylene <0.2  ND ND ND M-Xylene ND ND ND ND Styrene 0.2 ND ND NDa-Methyl Styrene 0.2 ND ND ND Vinyl Toluene 0.2 ND ND ND Indene 1.5 NDND ND Tetrachloroethene ND ND ND ND Trichloroethene ND ND ND ND Total2.2 ND ND ND Volatile organic compounds were measured according to headspace gas spectrometry/mass chromatography (GC-MS) In this method aheadspace sampler is interfaced with a gas chromatograph equipped with amass selective detector. The sample size is 0.1 grams of sample in a22.5 ml headspace vial Sampling conditioning temperature is 190° C. for30 minutes The detection limit for the components in the hot meltadhesives is 0.2 ppm

We can see in Table 4 that the levels of individual VOC of the inventivesamples are much lower than that of comparative samples, especially forpartially hydrogenated C9 samples. The levels of these VOCs of tracechemicals in the inventive samples are also significantly lower thanthat of comparative samples.

Example 2—Hygiene Adhesives

Adhesive formulations were also prepared for hygiene applications asshown in Table 5. Resin samples were used from Example 1 as shown inTable 5 to prepare the adhesive formulations. These hot melt adhesiveswere prepared by mixing polymer, resin, antioxidant, and oil using aZ-blade mixer until a homogeneous mixture was obtained. The temperatureduring mixing was about 160° C.

TABLE 5 Hygiene 1 Hygiene 2 (wt %) (wt %) Hydrocarbon resin PartiallyHydrogenated 60 resin Hydrocarbon resin Partially Hydrogenated 60 resinStyrene-Butadiene- Polimeri - Europrene ® 20 Styrene (SBS) SolT6414Copolymer Styrene-Isoprene- Kraton ® D1165 20 Styrene (SIS) CopolymerOil Petro Canada - Puretol ® 20 20 380D Antioxidant BASF - Irganox ®1010 0.2 0.2 Wt % is based on the weight of the adhesive composition.

Table 6 shows the volatile organic compound content of the comparativeand inventive hygiene adhesives. The inventive hygiene adhesive sampleshad VOC levels of 0.9 ppm and non-detectable while the comparativehygiene adhesive samples had VOC levels of 64.8 ppm and 28.6 ppm.

TABLE 6 Formulation Hygiene 1 Hygiene 2 Hygiene 1 Hygiene 2 Resin SampleCompar- Compar- Inven- Inven- ative 1 ative 4 tive 1 tive 2 Method ofadhesive z-blade z-blade z-blade z-blade preparation Methylene Chloride<0.2 ND ND ND Hexane <0.2 ND ND ND Chloroform <0.2 ND ND ND Cyclohexane5.2 0.3 ND ND Toluene 8.5 26.4  ND 0.9 Ethylcyclohexane 2.6 ND ND NDEthylbenzene 1.9 ND ND ND P-Xylene 0.8 ND ND ND O-Xylene ND ND ND NDM-Xylene ND ND ND ND Styrene 7.1 0.2 ND ND a-Methyl Styrene 6.8 0.3 NDND Vinyl Toluene 5.7 0.3 ND ND Indene 26.2 1.2 ND ND TetrachloroetheneND ND ND ND Trichloroethene ND ND ND ND Total 64.8 28.6  ND 0.9

Example 3—Packaging Adhesives

Adhesive formulations were also prepared for packaging applications asshown in Table 7. Resin samples were used from Example 1 as shown inTable 8 to prepare the adhesive formulations. These hot melt adhesiveswere prepared by mixing polymer, resin, antioxidant, and oil on a hotplate until a homogeneous mixture was obtained. The temperature duringmixing was about 160° C.

TABLE 7 Packaging Adhesive Formulation Packaging 1 (wt %) Hydrocarbonresin Partially Hydrogenated resin 45 EVA Arkema - Evatane ® 28150 35Wax Sasol - Sasol ® Wax H1 20 Antioxidant BASF - Irganox ® 1010 1 Wt %based on the adhesive composition

TABLE 8 Packaging Adhesive VOC Content Formulation Packaging 1 Packaging1 Resin Sample Comparative 1 Inventive 1 Method of adhesive preparationhot plate hand hot plate hand mixing mixing Samples Comparative 1Developmental 1 Methylene Chloride ND ND Hexane ND ND Chloroform ND NDCyclohexane 0.2 ND Toluene 0.5 ND Ethylcyclohexane <0.2  ND Ethylbenzene0.4 ND P-Xylene 0.2 ND O-Xylene <0.2  ND M-Xylene ND ND Styrene 1.8 <0.2a-Methyl Styrene 0.5 <0.2 Vinyl Toluene 1.4 <0.2 Indene 7.7  0.7Tetrachloroethene ND ND Trichloroethene ND ND Total 12.6   0.7

The data show that the inventive packaging adhesive had a VOC content of0.7 ppm while the comparative sample had a VOC content of 12.6 ppm.

Example 4—Automotive Adhesives

Adhesive formulations were also prepared for automotive applications asshown in Table 9. Resin samples were used from Example 1 as shown inTable 10 to prepare the adhesive formulations. These hot melt adhesiveswere prepared by mixing polymer, resin, antioxidant, and oil on a hotplate or with a Z-Blade mixer until a homogeneous mixture was obtained.The temperature during mixing was about 160° C.

TABLE 9 Automotive Adhesives Automotive 1 Automotive 2 (wt %) (wt %)Hydrocarbon Partially Hydrogenated 60 resin resin Hydrocarbon PartiallyHydrogenated 53.5 resin resin SBS Polimeri - Europrene ® 20 SolT6414 SBSTSRC - Vector ® 4186 36 Amorphous Eastman - Aerafin ® 180 Polyolefin(APO) Oil Petro Canada - Puretol ® 20 10 380D Antioxidant BASF -Irganox ® 1010 0.2 Antioxidant BASF - Irganox ® B225 0.5 Wt % is basedon the adhesive composition.

TABLE 10 Automotive Adhesives VOC Content Auto- Auto- Auto- Auto-Formulation motive - 1 motive 2 motive 1 motive 2 Resin Sample Compar-Compar- Inven- Inven- ative 1 ative 4 tive 1 tive 2 Method of adhesivehot plate z-blade hot plate z-blade preparation hand mixing hand mixingMethylene Chloride <0.2 ND ND ND Hexane <0.2 ND ND ND Chloroform <0.2 NDND ND Cyclohexane 5.2 5.2 ND <0.2 Toluene 8.5 1.0 ND <0.2Ethylcyclohexane 2.6 1.2 ND ND Ethylbenzene 1.9 0.3 ND ND P-Xylene 0.80.4 ND <0.2 O-Xylene ND 1.3 ND ND M-Xylene ND ND ND ND Styrene 7.1 1.5ND ND a-Methyl Styrene 6.8 1.9 ND <0.2 Vinyl Toluene 5.7 0.8 ND NDIndene 26.2 6.8 ND <0.2 Tetrachloroethene ND ND ND ND Trichloroethene NDND ND ND Total 64.8 20.4  ND <0.2

The data show that the inventive packaging adhesives had VOC contents of<0.2 ppm and not detectable while the comparative sample had VOCcontents of 64.8 and 20.4 ppm.

That which is claimed:
 1. A tackifier composition comprising at leastone thermoplastic hydrocarbon resin and an antioxidant composition;wherein a portion of the volatile organic compounds in the thermoplastichydrocarbon resin has been removed; wherein the antioxidant compositioncomprises at least one primary antioxidant and at least one secondaryantioxidant; and wherein the levels of individual volatile organiccompound monitored in the tackifier composition are less than about 0.5ppm as measured by GC/MS headspace analysis.
 2. The tackifiercomposition according to claim 1 wherein the thermoplastic hydrocarbonresin is at least one selected from the group consisting of pure monomerthermoplastic resin (PMR), C5 thermoplastic resin, C5/C9 thermoplasticresin, C9 thermoplastic resin, terpene thermoplastic resin,indene-coumarone (IC) thermoplastic resin, dicyclopentadiene (DCPD)thermoplastic resin, hydrogenated or partially hydrogenated pure monomer(PMR) thermoplastic resin, hydrogenated or partially hydrogenated C5thermoplastic resin, hydrogenated or partially hydrogenated C5/C9thermoplastic resin, hydrogenated or partially hydrogenated C9thermoplastic resin, hydrogenated or partially hydrogenateddicyclopentadiene (DCPD) thermoplastic resin, terpene thermoplasticresin, modified indene-coumarone (IC) thermoplastic resin, and mixturesthereof.
 3. The tackifier composition according to claim 1 wherein saidprimary antioxidant is at least one sterically hindered phenol selectedfrom the group consisting of CI-CXIX:

wherein R=C₈H₁₇ or C₁₈H₃₇

wherein R=C₈H₁₇ or c₁₂H₂₅;


4. The tackifier composition according to claim 1 wherein said primaryantioxidant is a secondary arylamines.
 5. The tackifier compositionaccording to claim 1 wherein said secondary antioxidant is at least oneselected from the group consisting of organo-phosphites, thioethers (ororganic sulfides), and hydroxyl-amines.
 6. The tackifier compositionaccording to claim 5 wherein said secondary amine is selected from thegroup consisting of 2, 2′,T-Nitrilo[triethyl-25tris[3,3,5,5-tetra-tert.-butyl-1,1-biphenyl-2,2diyl] phosphite (CAS80410-33-9); Bis(2,4-di-tert.-butyl-6-methylphenyl)-ethyl-phosphite (CAS145650-60-8); Bis-(2,4-ditert.-butylphenol)pentaerythritol diphosphate(CAS 26741-53-7); Tris(2,4-di-tert.butylphenyl) phosphite (CAS31570-04-4); Tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonite (CAS 119345-01-6); andTri-(nonylphenol)-phosphite
 30. 7. The tackifier composition accordingto claim 5 wherein said thioether antioxidant is at least one selectedfrom the group consisting of didodecyl-3,3′-thiodipropionate (CAS123-28-4) and 3,3′-Thiodipropionic acid dioctadecylester (CAS 693-36-7).8. The tackifier composition according to claim 5 wherein saidhydroxyl-amine is oxidized bis(hydrogenated tallow alkyl) amines (CAS:143925-92-2).
 9. The tackifier composition according to claim 1 whereinsaid hindered amine light stabilizer (HALS) is at least one selectedfrom the group consisting of A(1)-A(X):

wherein R=H, CH₃ or OC₈H₁₇


10. The tackifier composition according to claim 1 wherein the amount ofsaid primary antioxidant ranges from about 0.1% to about 1% based on theweight of the thermoplastic hydrocarbon resin.
 11. The tackifiercomposition according to claim 1 wherein the amount of said secondaryantioxidant ranges from about 0.1% to about 1% based on the weight ofsaid thermoplastic hydrocarbon resin.
 12. The tackifier compositionaccording to claim 1 wherein the amount of said HALS ranges from about0.05% to about 0.5% by weight based on the weight of said thermoplastichydrocarbon resin.
 13. The tackifier composition according to claim 1wherein said primary antioxidant is pentaerythritoltetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) and saidsecondary antioxidant is bis(2,2,6,6,-tetramethyl-4-piperidyl)sebaceate.14. An adhesive composition comprising at least one base polymer and atleast one tackifier composition.
 15. The adhesive composition accordingto claim 14 wherein said base polymer is selected from the groupconsisting ethylene vinyl acetate copolymer, ethylene n-butyl acrylatecopolymer, ethylene methyl acrylate copolymer, polyester, neoprene,acrylics, urethane, poly(acrylate), ethylene acrylic acid copolymer,polyether ether ketone, polyamide, styrenic block copolymers, randomstyrenic copolymers, hydrogenated styrenic block copolymers, styrenebutadiene copolymers, natural rubber, polyisoprene, polyisobutylene,atactic polypropylene, polyethylene including atactic polypropylene,ethylene-propylene polymers, propylene-hexene polymers, ethylene-butenepolymers, ethylene octene polymers, propylene-butene polymers,propylene-octene polymers, metallocene-catalyzed polypropylene polymers,metallocene-catalyzed polyethylene polymers, ethylene-propylene-butyleneterpolymers, copolymers produced from propylene, ethylene, and variousC4-C10 alpha-olefin monomers, polypropylene polymers, functionalpolymers such as maleated polyolefins, butyl rubber, polyestercopolymers, copolyester polymers, isoprene, the terpolymer formed fromthe monomers ethylene, propylene, and a bicyclic olefin (known as“EPDM”), isoprene-based block copolymers, butadiene-based blockcopolymers, acrylate copolymers such as ethylene acrylic acid copolymer,butadiene acrylonitrile rubber, and polyvinyl acetate.
 16. The adhesivecomposition of claim 14 wherein said tackifier composition comprisespentaerythritoltetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) andbis(2,2,6,6,-tetramethyl-4-piperidyl)sebaceate.
 17. The adhesivecomposition according to claim 14 wherein said adhesive composition is apressure sensitive adhesive (PSA) wherein said PSA comprises about 5parts to about 90 parts by weight of at least one base polymer; about 5parts to about 90 parts by weight of at least one tackifier composition;wherein the tackifier composition comprises at least one thermoplastichydrocarbon resin and an antioxidant composition; wherein a portion ofthe volatile organic compounds in the thermoplastic hydrocarbon resinhas been removed; wherein the antioxidant composition comprises at leastone primary antioxidant, optionally at least one secondary antioxidant,and at least one HALS; and wherein the levels of individual volatileorganic compounds of interest in the tackifier composition are less thanabout 0.5 ppm as measured by GC/MS headspace analysis as described inthis disclosure; 0 to about 50 parts by weight of at least oneplasticizer; 0 to about 50 parts by weight of at least one wax; 0 toabout 1 part by weight of at least one additional antioxidant; and 0 toabout 80 parts by weight of at least one filler.
 18. An articlecomprising the adhesive composition of claim 14.